A belated hello from me, also a fellow Datcheteer, Datchoid, Dachshund, whatever we're called…
I'm similar to your good self, relative newby to road riding, 1000miles up on the
road bike, a black/blue Giant TCR.
70 milers would be OK assuming pace not too mad. I'm 42 (but feeling 52 at the mo).
There's a
group out of Denham on Saturday and Sunday mornings that might suit you if you fancy group riding. I rode with them a lot last year but lost my fitness over winter
and now don't dare go back until I get back up to speed…